A system of practical medicine. By American authors. Vol. 4

by Unknown

M.—Sig. Apply with a sponge or rag, shaking well before using.

The annexed is also a good stimulating lotion:

Rx.	Sulphuris præcipitati,	drachm ij;
	Ætheris,	fluidrachm iv;
	Aquæ cologniensis,	fluidrachm iv;
	Alcoholis,	fluidounce iij.

M.—Sig. Shake well and dab on with a rag.

Potassium sulphide is a preparation of sulphur which often acts admirably in this disease. It may be employed as an ointment, or, preferably, as a lotion. An excellent formula, containing the sulphide, which can be prescribed with advantage in many cases, is the following:

Rx.	Potassii sulphidi, Zinci sulphatis, aa.	drachm j;
	Aquæ rosæ,	fluidounce iv.

M.—S. Apply with a sponge or rag. The resulting lotion from this mixture is a complex one, a double reaction taking place. The salts should be separately dissolved, and then mixed. If properly made, the lotion when shaken is of a milky color and free from odor; upon standing the particles sink and form a white sediment, the liquid above being clear. If improperly prepared, as is often the case, it is of a yellowish tinge with a decided odor of the potassium sulphide, and has an entirely different effect. Vleminckx's solution,⁴ perfumed with an essential oil, is often of service; it is to be diluted with three to six parts of water and dabbed on every night, the strength gradually increased if necessary.

⁴ See treatment of Psoriasis for formula.

Another class of external remedies found of service in the treatment of this disease are the mercurials. They are not so valuable as the sulphur preparations. Corrosive sublimate, white precipitate, and calomel are the mercurials commonly used. If sulphur has been previously employed, several days should intervene and the parts be repeatedly cleansed before using a mercurial, otherwise the skin is darkened temporarily by the formation of the black sulphuret of mercury. Corrosive sublimate is prescribed in the form of a lotion, from one-half to two grains to the ounce of alcohol and water, or as in the following formula: